Processing of payment transactions, such as at time of tendering of a credit card during checkout at a store, triggers generation and transmission of a payment request from a merchant payment tendering device or system to a payment transaction processing system over a network. Payment request are then processed according to defined payment processes, which may include routing to other systems and services. A payment request is subject to a timeout period on the merchant payment tendering device or system. When a response is not received over the network by the merchant payment tendering device or system within the timeout period, the timeout period expires and the payment request fails.